Gudas J M, Knight G B, Pardee A B
Division of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts.
Mol Cell Biol. 1990 Oct;10(10):5591-5. doi: 10.1128/mcb.10.10.5591-5595.1990.
Concomitant with the onset of S phase, a series of thymidine kinase (TK) splicing intermediates as well as mature TK mRNA accumulates in the nucleus of BALB/c 3T3 cells. Most of the TK splicing intermediates are retained by oligo(dT)-cellulose chromatography, and, therefore, 3' end formation and polyadenylation probably precede the splicing of TK pre-mRNAs. We have further characterized the TK pre-mRNAs that are present in the nuclei of S-phase cells by using specific probes derived from each of the six TK intervening sequences. Based on the sizes of the pre-mRNAs and their patterns of hybridization with these intron probes, we propose a pathway for intron removal from nascent TK transcripts. Intron excision occurred by a preferred, but not necessarily obligatory, order which appears to have been conserved in mouse and Chinese hamster cells.
与S期开始同时，一系列胸苷激酶（TK）剪接中间体以及成熟的TK mRNA在BALB/c 3T3细胞核中积累。大多数TK剪接中间体可通过寡聚（dT）-纤维素层析保留，因此，3'端形成和聚腺苷酸化可能先于TK前体mRNA的剪接。我们通过使用源自六个TK间隔序列中每个序列的特异性探针，进一步对S期细胞核中存在的TK前体mRNA进行了表征。根据前体mRNA的大小及其与这些内含子探针的杂交模式，我们提出了从新生TK转录本中去除内含子的途径。内含子切除按优先但不一定是必需的顺序发生，这一顺序在小鼠和中国仓鼠细胞中似乎是保守的。
